//
// WebSocketServer.cpp
//
// This sample demonstrates the WebSocket class.
//
// Copyright (c) 2012, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier:	BSL-1.0
//

#include "Poco/Net/HTTPServer.h"
#include "Poco/Net/HTTPRequestHandler.h"
#include "Poco/Net/HTTPRequestHandlerFactory.h"
#include "Poco/Net/HTTPServerParams.h"
#include "Poco/Net/HTTPServerRequest.h"
#include "Poco/Net/HTTPServerResponse.h"
#include "Poco/Net/HTTPServerParams.h"
#include "Poco/Net/SecureServerSocket.h"
#include "Poco/Net/ServerSocket.h"
#include "Poco/Net/WebSocket.h"
#include "Poco/Net/NetException.h"
#include "Poco/Util/ServerApplication.h"
#include "Poco/Util/Option.h"
#include "Poco/Util/OptionSet.h"
#include "Poco/Util/HelpFormatter.h"
#include "Poco/Format.h"
#include <Poco/Thread.h>

#include <iostream>
#include <thread>

using Poco::Net::SecureServerSocket;
using Poco::Net::ServerSocket;
using Poco::Net::WebSocket;
using Poco::Net::WebSocketException;
using Poco::Net::HTTPRequestHandler;
using Poco::Net::HTTPRequestHandlerFactory;
using Poco::Net::HTTPServer;
using Poco::Net::HTTPServerRequest;
using Poco::Net::HTTPResponse;
using Poco::Net::HTTPServerResponse;
using Poco::Net::HTTPServerParams;
using Poco::Net::Context;
using Poco::Timestamp;
using Poco::ThreadPool;
using Poco::Util::ServerApplication;
using Poco::Util::Application;
using Poco::Util::Option;
using Poco::Util::OptionSet;
using Poco::Util::HelpFormatter;

class PageRequestHandler : public HTTPRequestHandler
/// Return a HTML document with some JavaScript creating
/// a WebSocket connection.
{
public:
    void handleRequest(HTTPServerRequest &request, HTTPServerResponse &response)
    {
        std::cout << "PageRequestHandler thread_id is : " << std::this_thread::get_id() << std::endl;
        response.setChunkedTransferEncoding(true);
        response.setContentType("text/html");
        std::ostream &ostr = response.send();
        ostr << "<html>";
        ostr << "<head>";
        ostr << "<title>WebSocketServer</title>";
        ostr << "<script type=\"text/javascript\">";
        ostr << "function WebSocketTest()";
        ostr << "{";
        ostr << "  if (\"WebSocket\" in window)";
        ostr << "  {";
        ostr << "    var ws = new WebSocket(\"ws://" << request.serverAddress().toString() << "/ws\");";
        ostr << "    ws.onopen = function()";
        ostr << "      {";
        ostr << "        ws.send(\"Hello, world!\");";
        ostr << "      };";
        ostr << "    ws.onmessage = function(evt)";
        ostr << "      { ";
        ostr << "        var msg = evt.data;";
        ostr << "        alert(\"Message received: \" + msg);";
        ostr << "        ws.close();";
        ostr << "      };";
        ostr << "    ws.onclose = function()";
        ostr << "      { ";
        ostr << "        alert(\"WebSocket closed.\");";
        ostr << "      };";
        ostr << "  }";
        ostr << "  else";
        ostr << "  {";
        ostr << "     alert(\"This browser does not support WebSockets.\");";
        ostr << "  }";
        ostr << "}";
        ostr << "</script>";
        ostr << "</head>";
        ostr << "<body>";
        ostr << "  <h1>WebSocket Server</h1>";
        ostr << "  <p><a href=\"javascript:WebSocketTest()\">Run WebSocket Script</a></p>";
        ostr << "</body>";
        ostr << "</html>";
    }
};

class WebSocketRequestHandler : public HTTPRequestHandler
/// Handle a WebSocket connection.
{
public:
    void handleRequest(HTTPServerRequest &request, HTTPServerResponse &response)
    {
        std::cout << "WebSocketRequestHandler thread_id is : " << std::this_thread::get_id() << std::endl;
        Application &app = Application::instance();
        try {
            WebSocket ws(request, response);
            app.logger().information("WebSocket connection established.");
            char buffer[1024];
            int flags;
            int n;
            do {
                n = ws.receiveFrame(buffer, sizeof(buffer), flags);
                app.logger().information(Poco::format("Frame received (length=%d, flags=0x%x).", n, unsigned(flags)));
                ws.sendFrame(buffer, n, flags);
            } while (n > 0 && (flags & WebSocket::FRAME_OP_BITMASK) != WebSocket::FRAME_OP_CLOSE);
            app.logger().information("WebSocket connection closed.");
        } catch (WebSocketException &exc) {
            app.logger().log(exc);
            switch (exc.code()) {
            case WebSocket::WS_ERR_HANDSHAKE_UNSUPPORTED_VERSION:
                response.set("Sec-WebSocket-Version", WebSocket::WEBSOCKET_VERSION);
                // fallthrough
            case WebSocket::WS_ERR_NO_HANDSHAKE:
            case WebSocket::WS_ERR_HANDSHAKE_NO_VERSION:
            case WebSocket::WS_ERR_HANDSHAKE_NO_KEY:
                response.setStatusAndReason(HTTPResponse::HTTP_BAD_REQUEST);
                response.setContentLength(0);
                response.send();
                break;
            }
        }
    }
};

class RequestHandlerFactory : public HTTPRequestHandlerFactory
{
public:
    HTTPRequestHandler *createRequestHandler(const HTTPServerRequest &request)
    {
        Application &app = Application::instance();
        std::cout << "RequestHandlerFactory thread_id is : " << std::this_thread::get_id() << std::endl;
        app.logger().information("Request from "
                                 + request.clientAddress().toString()
                                 + ": "
                                 + request.getMethod()
                                 + " "
                                 + request.getURI()
                                 + " "
                                 + request.getVersion());

        for (HTTPServerRequest::ConstIterator it = request.begin(); it != request.end(); ++it) {
            // app.logger().information(it->first + ": " + it->second);
        }

        if (request.find("Upgrade") != request.end() && Poco::icompare(request["Upgrade"], "websocket") == 0)
            return new WebSocketRequestHandler;
        else
            return new PageRequestHandler;
    }
};

class WebSocketServer : public Poco::Util::ServerApplication
/// The main application class.
///
/// This class handles command-line arguments and
/// configuration files.
/// Start the WebSocketServer executable with the help
/// option (/help on Windows, --help on Unix) for
/// the available command line options.
///
/// To use the sample configuration file (WebSocketServer.properties),
/// copy the file to the directory where the WebSocketServer executable
/// resides. If you start the debug version of the WebSocketServer
/// (WebSocketServerd[.exe]), you must also create a copy of the configuration
/// file named WebSocketServerd.properties. In the configuration file, you
/// can specify the port on which the server is listening (default
/// 9980) and the format of the date/time string sent back to the client.
///
/// To test the WebSocketServer you can use any web browser (http://localhost:9980/).
{
public:
    WebSocketServer()
        : _helpRequested(false)
    {
    }

    ~WebSocketServer()
    {
    }

protected:
    void initialize(Application &self)
    {
        loadConfiguration(); // load default configuration files, if present
        ServerApplication::initialize(self);
    }

    void uninitialize()
    {
        ServerApplication::uninitialize();
    }

    void defineOptions(OptionSet &options)
    {
        ServerApplication::defineOptions(options);

        options.addOption(
            Option("help", "h", "display help information on command line arguments")
                .required(false)
                .repeatable(false));
    }

    void handleOption(const std::string &name, const std::string &value)
    {
        ServerApplication::handleOption(name, value);

        if (name == "help")
            _helpRequested = true;
    }

    void displayHelp()
    {
        HelpFormatter helpFormatter(options());
        helpFormatter.setCommand(commandName());
        helpFormatter.setUsage("OPTIONS");
        helpFormatter.setHeader("A sample HTTP server supporting the WebSocket protocol.");
        helpFormatter.format(std::cout);
    }

    int main(const std::vector<std::string> &args)
    {
        std::cout << "WebSocketServer main thread_id is : " << std::this_thread::get_id() << std::endl;
        if (_helpRequested) {
            displayHelp();
        } else {
            // get parameters from configuration file
            unsigned short port = (unsigned short)config().getInt("WebSocketServer.port", 9980);

            // set-up a server socket
            ServerSocket svs(port);

            // set-up a server socket ssl
            // Context::Ptr pContext = new Context(Context::SERVER_USE, "", "", "", Context::VERIFY_NONE, 9, true, "ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH");
            // SecureServerSocket svs(port, 64, pContext);
            // set-up a HTTPServer instance
            HTTPServer srv(new RequestHandlerFactory, svs, new HTTPServerParams);
            // start the HTTPServer
            srv.start();
            // wait for CTRL-C or kill
            waitForTerminationRequest();
            // Stop the HTTPServer
            srv.stop();
        }
        return Application::EXIT_OK;
    }

private:
    bool _helpRequested;
};

int main(int argc, char *argv[])
{
    std::cout << "main thread_id is : " << std::this_thread::get_id() << std::endl;
    WebSocketServer server;
    return server.run(argc, argv);
}